Photographic silver halide light-sensitive elements useful in preventing yellow fog

ABSTRACT

A photographic silver halide light-sensitive element comprising a support having thereon at least one layer containing a silver halide, wherein one colloid containing layer of said element contains:

United States Patent Inventors Tatsuya Tajima;

Kunioki Ohmura, both of Kanagawa, Japan Appl. No. 761,858

Filed Sept. 23, 1968 Patented Oct. 26, 1971 Assignee Fuji Photo FilmCo., Ltd.

Kanagawa, Japan Priority Sept. 22, 1967 Japan 42/6092] PHOTOGRAPHICSILVER HALIDE LIGHT- SENSITIVE ELEMENTS USEFUL IN PREVENTING YELLOW FOG4 Claims, No Drawings US. Cl 96/67, 96/109 Int. Cl G03c l/76, G030 3/00,G03c l/34 Field of Search 96/67, 109

[56] References Cited UNITED STATES PATENTS 3,144,336 8/1964 l-lerz96/109 3,466,173 9/1969 Ishikawa 96/109 FOREIGN PATENTS 948,442 2/1964Great Britain Primary Examiner-Norman G. Torchin Assistant ExaminerMaryF, Kelley Attorney- Sughrue, Rothwell, Mion, Zinn & MacPeak ABSTRACT: Aphotographic silver halide light-sensitive element comprising a supporthaving thereon at least one layer containing a silver halide, whereinone colloid containing layer of said element contains: a) a compound ofthe formula M10 0r M10 wherein M is a hydrogen atom, an alkaline metalatom or ammonium group, and b) at least one of the following:unsubstituted benzenesulfinic acid, substituted benezenesulfinic acidand salts thereof; This element exhibits a marked reduction in theamount of yellow fog which is formed after storage and/0r development.

BACKGROUND OF THE INVENTION Field of the Invention The present inventionrelates to a photographic silver halide light-sensitive element in whichthe formation of yellow fogs is reduced.

Description of the Prior Art An exposed photographic silver halidelight-sensitive element is usually successively processed in adeveloping bath, a stopping bath and a fixing bath. In this case, athiosulfate, a solvent for a silver halide which is contained in thefixing bath, is frequently intermixed in a developer. Also, in the caseof processing an exposed photographic silver halide light-sensitiveelement in a monobath for development and fixing simultaneously, athiosulfate which is a solvent for a silver halide is sometimesincorporated in the monobath.

When photographic silver halide light-sensitive elements are developedin such a developing bath (or a monobath for development and fixingsimultaneously) containing a solvent for silver halide, yellow fogsare-produced, the extent of the fogs depending upon the kind of thelight-sensitive element.

In particular, in photographic printing papers, the formation of yellowfogs is more developed than in other photographic silver halidelight-sensitive elements, and to prevent the formation of fogs, variousantifoggants have been used.

In most cases, yellow fogs in photographic silver halide light-sensitiveelements are caused by fine silver particles or silver sulfide depositedin any water-permeable colloid layer used in forming the photographicsilver halide light-sensitive elements, not generally in baryta layersor emulsion layers thereof, or in water-permeable papers. The reason forthe formation of such yellow fogs is as follows:

When a photographic silver halide light-sensitive element is processedin a developer containing a solvent for a silver halide, such as athiosulfate, and when a material capable of forming a nucleus forreducing water-soluble silver ions to metallic silver, such as colloidalsulfur, silver or silver sulfide is present in a baryta layer or anemulsion layer thereof is present, water-soluble silver ions are reducedinto metallic silver by reducing agents (for example a developing agent)in the developer, and these deposit on the aforesaid nuclei, thusforming the yellow fogs.

The yellow fogs thus formed can be generally divided into two types,according to their method of formation. One method is where theformation of yellow fogs is observed when a photographic silver halidelight-sensitive element is developed in a developer containing a solventfor silver halide, just after the preparation thereof. A second methodis where the formation of yellow fogs is not observed when aphotographic silver halide light-sensitive element is developed in adevelopercontaining a solvent for silver halide (just after thepreparation thereof), but is observed when a photographic silver halidelight-sensitive element is subjected to the same processing after it isstored under various conditions.

The former is the situation when a material capable of being a nucleusfor reducing water-soluble silver ions to metallic silver is alreadypresent in a baryta paper as a support for a photographic silver halidelight-sensitive element, or else is present in a silver halidelight-sensitive emulsion layer, a baryta paper, or a paper for aphotographic silver halide lightsensitive element at the preparationthereof. The latter case is where a material capable of forming anucleus for reducing water-soluble silver ions to metallic silver isformed in the emulsion layer, the baryta layer of the support of thephotographic element, after it has been stored under various conditions.For example, when photographic printing papers are packed and stored fora long period of time, yellow fogs are formed, in particular at theedges of the printing papers or at the uppermost sheet of thephotographic printing paper. This shows that the formation of a nucleusutilized for reducing water-soluble silver ions to metallic silver isparticularly great at portions which are liable to be contacted by theatmosphere.

SUMMARY OF THE INVENTION It has been found that a photographic silverhalide-sensitive element which contains at least one colloid layer whichcontains a compound capable of forming iodate ions will exhibit a markedreduction in the amount of yellow fogs which may be formed therein. Toprolong the effect of the iodate-forming compound after storage,benzenesulfinic acids and salts thereof, may be added.

Representative compounds capable of forming iodate ions are iodic acid,periodic acid and salts thereof.

Various substituted benzenesulfinic acids, and salts thereof aredescribed in the specification.

Representative colloidal materials wherein the compound of the presentinvention may be incorporated include emulsion layers, protective layersand baryta layers.

Thus, an object of this invention is to prevent the formation of yellowfogs in photographic silver halide light-sensitive elements, and inparticular to prevent the formation of yellow fogs in photographicsilver halide light-sensitive elements when they are stored or allowedto stand for long periods of time under various conditions.

Another object of this invention is to provide a photographic silverhalide light-sensitive element in which the formation of yellow fogs iseffectively reduced or prevented.

DESCRIPTION OF THE PREFERRED EMBODIMENTS These objects of this inventioncan be attained by incorporating in a support paper for photographicprinting paper or in at least one layer of the colloidal layers oremulsion layers formed on a support for photographic silver halidelight-sensitive elements, a compound capable of forming iodate ions(hereinafter such a compound is called an iodate compound) togetherwith, if necessary, an unsubstituted or substituted benzenesulfinicacid, or a salt thereof.

In the claims and the specifications of this invention, the colloidlayers include every layer which contains colloidal materials forphotographic silver halide light-sensitive elements, such as, emulsionlayers, protective layers, and baryta layers. Thus, the factors whichcause yellow fogs are, as mentioned above, due to the propertiesspecific to the material which is used. However, it is believed thatlower molecular weight materials contained in a colloid layer or a paperbase move freely through each layer when each colloid layer of thephotographic silver halide light-sensitive element is swollen in aprocessing bath. In fact, the aforesaid material (such as an iodinecompound, unsubstituted or substituted benzenesulfinic acid, or a saltthereof) may be effectively incorporated in any of the colloid layersand the paper base, and thus may, in effect, be incorporated in anylayer in the present invention.

A compound capable of forming iodate ions (l0 that is an iodatecompound, is generally a compound as iodic acid, periodic acid or a saltthereof, represented by M10, or MlO wherein M represents a hydrogenatom, an alkali metal or an ammonium group. As illustrative examples ofsuch compounds, there are ammonium iodate, iodic acid, sodium iodate,periodic acid, potassium periodate, ammonium periodate, and the like.

The unsubstituted or substituted benzenesulfinic acids or salts thereof,may generally be represented by the general formula:

wherein M represents a hydrogen atom, an alkali metal or ammonium group,and X represents hydrogen, a halogen atom, an alkyl group having 1-3carbon atoms, or an amino group. Illustrative examples of such compoundsare sodium benzenesulfinate, sodium p-toluenesulfinate, sodiumpchlorobenzenesulfinate, and sodium p-aminobenzenesulfinate.

The mechanism of the iodate compound of this invention for preventingthe formation of yellow fogs has not yet been clarified, but thefollowing is offered as a nonlimitative possible explanation. The yellowfogs form in the silver halide emulsion layer of a photographic silverhalide light-sensitive element or at the interface between the silverhalide emulsion layer and an adjacent layer thereof. Hence, the yellowfogs are considered to be formed through a stage where physicaldevelopment nuclei are formed or present. Thus, yellowish developedsilver as formed, utilizing the physical development nuclei as thedevelopment nuclei when the photographic silver halide light-sensitiveelement is developed in a developing bath containing a solvent for asilver halide. It is believed proper to consider the physicaldevelopment nuclei as very fine particles of metallic silver (A,) formedin the silver halide emulsion layer or at the interface between thesilver halide emulsion layer and a layer adjacent the silver halideemulsion layer, the nuclei being formed by the reduction of silver ions(Af). Alternatively, they may be considered as very fine particles ofsilver sulfide formed there by the reaction of silver ions (AJ) and avery small amount of a sulfur compound. In the former case, the iodatewill suppress the formation of metallic silver by oxidizing materialswhich will reduce silver ions, while in the latter case the iodatecompound will suppress the formation of silver sulfide by oxidizing thesulfur compound. Therefore, by incorporating the iodate compound in aphotographic colloid layer of a photographic silver halidelight-sensitive element the formation of the physical development nucleiwill be suppressed, and the formation of yellow fogs can be reduced.

Furthermore, it has been found that by adding an unsubstituted orsubstituted benzenesulfinic acid, or a salt thereof, to the colloidlayer, the effect of the iodate compound can be prolonged for an evenlonger period of time. That is, after storing a photographic silverhalide light-sensitive element containing an iodate compound therein fora long period of time, or else after allowing it to stand underconditions of high temperature and high humidity, the photographiclight-sensitive element can be subjected to development, fixing, andwashing as usual. It will then be observed that the unexposed portionsof the photographic silver halide light-sensitive element becomeyellowish, caused perhaps by the spontaneous decomposition of the iodatecompound. However, when an unsubstituted or substituted benzenesulfinicacid or a salt thereof is incorporated in the light-sensitive element,the spontaneous decomposition of the iodate compound is suppressed,thereby further inhibiting the occurrence of yellowmg.

In other words, it is believed that the formation of yellow fogs isprevented or suppressed by an iodate compound, and the spontaneousdecomposition of the iodate compound is prevented, or suppressed, by anunsubstituted or substituted benzenesulfinic compound, or a saltthereof.

In the present invention, an iodate compound, M or MIC may be employedalone, or as a mixture of two or more types of such iodate compounds. Asmentioned above, if necessary, an unsubstituted or benzenesulfinic acid,or a salt thereof, may be used with the aforesaid iodate compound. Inthis case, the benzenesulfinic acid, or salt thereof, may be used along,or as a mixture of two or more types thereof.

There are no particular limitations with respect to the amounts of theaforesaid additives, but generally the amount of the iodate compound ispreferably about 0.5 g. per kilogram of silver halide emulsion(containing about 40 g. of silver halide).

Also, in the present invention, the aforesaid additives may beeffectively added in any colloid layer of a photographic silver halidelight-sensitive element and also they may be added in one colloid layeror two or more colloid layers. Furthermore, the additives may beincorporated in a colloid layer at any stage, but usually it isincorporated in a colloid, such as, a silver halide emulsion, a barytacoating composition, a dispersion for use as a protective layer, etc.,at the preparation thereof, together with other additives, such ashardening agents, and wetting agents.

Thus, according to the present invention, a photographic silver halidelight-sensitive element capable of providing sharp images havingsubstantially no fogs or, at worst, very few fogs, is obtained.

The invention will now be explained with reference to the followingexamples.

EXAMPLE 1 A baryta coating composition, containing a hardening agent, awetting agent, etc., was applied to a paper in such proportions that theamounts of barium sulfate (anhydrous, gelatin, and sodium iodate(anhydrous) were 40 g., 4 g., and 0.05 g., respectively, per 1 squaremeter of the paper, to provide a baryta paper. Further, a photographicsilver halide emulsion for photographic printing paper use was appliedto the baryta layer thus formed to provide a photographic printingpaper.

As a comparative sample, a printing paper was prepared by the sameprocedure as above using the baryta coating composition containing nosodium iodate.

These printing papers were stored for 6 months at a temperature of 20 C.and at a relative humidity of 70 percent. Thereafter, they weredeveloped for 5-10 minutes at 20 C. in a developer having the followingcomposition:

Monomethyl p-aminophenol sulfate 3 g, Sodium sulfite (anhydrous) 45 g.Hydroquinone 12 g. Sodium carbonate (anhydrous) 67.5 g. Potassiumbromide 2 g.

Sodium thiosulate l 3. Water to make 3,000 ml.

The printing papers thus developed were fixed, washed and dried usingstandard techniques.

When the printing papers thus processed were compared as to the amountof yellow fog, the formation of yellow fog in the printing papercontaining sodium iodate was much less than that in the comparativesample.

EXAMPLE 2 A silver chlorobromide emulsion containing 50 mole percentsilver bromide and 0.5 g. of sodium iodate (anhydrous) per kilogram ofthe silver halide emulsion (containing 50 g. of silver halide), with adye sensitize-r, an antifoggant, a hardening agent, a wetting agent,etc., was applied to a baryta-coated paper to prepare a photographicprinting paper. When the printing paper thus prepared was processed asin example 1, the formation of yellow fogs was negligible.

EXAMPLE 3 A silver iodobromide emulsion containing 3 mole percent silveriodide and l g. of sodium iodate (anhydrous) per kilogram of the silverhalide emulsion, together with a dye sensitizer, a hardening agent, awetting agent, etc., was applied to a film base of triacetyl celluloseat a thickness of g./m. to provide a photographic silver halidelight-sensitive film was prepared by the same procedure as above whileusing a silver halide emulsion having the same composition as above,with the exception that no sodium iodate was contained therein.

When the photographic light-sensitive films were processed as in example1, yellow fogs were formed in the comparative photographiclight-sensitive film, while such fogs were not formed in thephotographic light-sensitive film of this invention.

EXAMPLE 4 A pure silver halide emulsion, containing 50 g. of silverchloride and 1.5 g. of sodium benzenesulfinate per kilogram of silverhalide emulsion, together with a hardening agent, a wetting agent, andthe like. was applied to a baryta-coated paper at a thickness of 50-80g./m. To the emulsion layer thus formed there was applied, as aprotective layer, an aqueous gelatin solution having the followingcomposition:

Gelatin 25 g. Sodium iodate (anhydrous) l g. Saponin (6% solution) 5 ml.Water 1,000 ml.

at a thickness of 30-50 ml./m. to thereby provide a photographicprinting paper. When the photographic printing paper thus prepared wasprocessed as in example 1 after storing for a long period of time, noyellow fogs were observed.

Moreover, when the photographic printing paper and the photographicsilver halide light-sensitive elements prepared in examples 1, 2 and 3were stored at conditions of high temperature and high humidity and thenprocessed asin example 1, yellow fogs (not as above, but yellow fogscaused by the decomposition of the iodate compound) were observed in thelight-sensitive elements prepared in examples 1, 2 and 3, but no suchyellow fogs were formed in the photographic printing paper whichcontained sodium iodate and sodium benzenesulfinate (ex. 4).

EXAMPLES 5-7 By the same procedure as in the aforesaid examples,photographic printing papers were formed, each having a light-sensitivesilver halide emulsion layer containing the additive or additives shownin the following table. After processing these printing papers as inexample 1, the reflection density of the yellow fogs was measured usinga filter transmitting blue light having wave lengths shorter than 500 m.The results are shown in the following table.

which contained the unsubstituted or substituted benzenesulfinic acidbut which contained no iodate compound, a large amount of yellow fogswere formed when they were stored for 6 months at a temperature of 20 C.and a relative humidity of 70 percent, or under high temperature andhigh humidity conditions.

On the other hand, when the sample of this invention of example 5 wasstored for a long period of time under atmospheric conditions, theformation of yellow fogs was extremely small, when compared with theaforesaid comparative samples. In addition, when the samples of thisinvention of examples 6 and 7 were stored for 6 months at a temperatureof 20 C. and at a relative humidity of 70 percent, or else under hightemperature and high humidity conditions, a yellow fog increase wasscarcely observable.

What is claimed is:

l. A photographic silver halide light-sensitive element useful inpreventing yellow fog comprising a support having thereon at least onelayer containing a silver halide, and one colloid layer selected fromthe group consisting of a photographic silver halide emulsion layer anda layer adjacent to a silver halide emulsion layer, wherein said colloidlayer of said element contains:

a. a compound of the formula MlO or M10 wherein M is a hydrogen atom, analkaline metal atom or an ammonium group, and

b. a member selected from the group consisting of unsubstitutedbenzenesulfinic acid, substituted benzenesulfinic acid, and saltsthereof.

2. The photographic silver halide light-sensitive element as claimed inclaim 1 wherein said salt of benzenesulfinic acid is sodiumbenzenesulfinate.

3. The photographic silver halide light-sensitive element as claimed inclaim 1 wherein said salt of a substituted benzenesulfinic acid isselected from the group consisting of sodium-p-toluenesulfinate, sodiump-chlorobenzenesulfinate, and sodium p-aminobenzenesulfinate.

TABLE 1 7 Reflection density of yellow tog using blue- Sample AdditiveAmount Initial filter (developed for 10 minutes) (gl/cm period For 6months at 20 For 5 days at C. C. and 70% RH and at 80% RH C t'v Ex. 1None 0.04 0.12 0.08 iax iiigigisff 3 Ammonium iodate (anhydrous) 0.05 0.04 0.07 0.07 Example 6 d0 05 v ,r Sodium benzenesiulfirzatcfin 0. 04 0.04 0. 04 1 7 Potassiumperio ate an y ou Emmp e Sodium p-t0l1lellt2lS1?lfiIlB.t6 82 (3 8:

Com arative Ex. 2) Sodium bonzenes mate i. EComBarative Ex. 3)P-toluenesulfinate- 0. 10 0. 04 0. 12 0, 03

As is clear from the results shown in the table, in the com- The P P PSilver hand}? lighbsensitiv? element 9 p'arative sample hi h containedno iodate compound as a claim 1 wherein the amount of the iodatecompound present [5 yellow fog preventing agent, and the comparativesample 0.5 grams per kg. of silver halide emulsion.

2. The photographic silver halide light-sensitive element as claimed inclaim 1 wherein said salt of benzenesulfinic acid is sodiumbenzenesulfinate.
 3. The photographic silver halide light-sensitiveelement as claimed in claim 1 wherein said salt of a substitutedbenzenesulfinic acid is selected from the group consisting of sodiump-toluenesulfinate, sodium p-chlorobenzenesulfinate, and sodiump-aminobenzenesulfinate.
 4. The photographic silver halidelight-sensitive element of claim 1 wherein the amount of the iodatecompound present is 0.5 grams per kg. of silver halide emulsion.